[llvm-commits] [llvm] r45403 - in /llvm/trunk/lib/Transforms/Scalar: InstructionCombining.cpp SCCP.cpp

[Chris Lattner]

On Jan 2, 2008, at 11:56 AM, Christopher Lamb wrote:
> For embedded devices with special address spaces often 0x0 is a  
> valid address in those spaces.

Ok, fair enough.

> I knew this was going to be a troublesome issue as it goes against  
> a basic assumption for single address space compilation. I know  
> that this assumption is salted away in xforms scattered throughout  
> the compiler, and I'm resigned to addressing them as they become  
> evident.

Ok.

> I would appreciate some advice on how to provide target specific  
> information to analysis and transforms (alias analysis could also  
> benefit from target specific address space information). Is there  
> an example where this is already being done?

There isn't a really good way to do this, as we don't want target- 
independent xforms (like instcombine) being overly parameterized by  
the target.  I think your solution of disabling this for non-default  
pointers is a good way to go.

Thanks!

-Chris